From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx206.postini.com [74.125.245.206]) by kanga.kvack.org (Postfix) with SMTP id 577AE6B004A for ; Fri, 24 Feb 2012 12:31:10 -0500 (EST) Received: from /spool/local by e4.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 24 Feb 2012 12:31:08 -0500 Received: from d01relay06.pok.ibm.com (d01relay06.pok.ibm.com [9.56.227.116]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id E77A238C8070 for ; Fri, 24 Feb 2012 12:25:31 -0500 (EST) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q1OHPNVX1229012 for ; Fri, 24 Feb 2012 12:25:23 -0500 Received: from d03av05.boulder.ibm.com (loopback [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q1OHPML4009508 for ; Fri, 24 Feb 2012 10:25:22 -0700 Message-ID: <4F47C800.4090903@linux.vnet.ibm.com> Date: Fri, 24 Feb 2012 09:25:20 -0800 From: Dave Hansen MIME-Version: 1.0 Subject: Re: [RFC][PATCH] fix move/migrate_pages() race on task struct References: <20120223180740.C4EC4156@kernel> <4F468F09.5050200@linux.vnet.ibm.com> <4F469BC7.50705@linux.vnet.ibm.com> <4F47BF56.6010602@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: "Eric W. Biederman" , linux-kernel@vger.kernel.org, linux-mm@kvack.org On 02/24/2012 09:08 AM, Christoph Lameter wrote: > cpuset_mems_allowed takes a mutex. Hmmm... Under rcu? > > security_task_movememory does some kind of security hook. > > Is that all safe? If not then we need to take a refcount on the task > struct after all. Urg, no we can't sleep under an rcu_read_lock(). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org